Zircon
On the label: Zircon · Gemstone
What it is
A natural zirconium silicate (not cubic zirconia), Mohs 6.5 to 7.5, with high brilliance; blue zircon is heat-treated. The December birthstone alongside tanzanite and turquoise.
Gemstones: Natural gemstones, as mined and cut. Hardness (Mohs scale) says what scratches what; treatment (heat, oil, dye) must be disclosed under FTC rules.
Wikidata: Mineral belonging to the group of nesosilicates. Q178928 →
In the research
12 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:
- Initial Performance Evaluation of an Ultraviolet 157 nm Laser Ablation System for ICP-MS Analysis · Analytical chemistry, 2026
- Ultraviolet light induced photocatalytic behavior of hydrothermally synthesized tetragonal zircon type bismuth vanadate nanoparticles · Talanta, 2026
- Microwave-Assisted Synthesis of Visible Light-Driven BiVO(4) Nanoparticles: Effects of Eu(3+) Ions on the Luminescent, Structural, and Photocatalytic Properties · Molecules (Basel, Switzerland), 2025
A paper is a paper, not a verdict: titles are listed so you can read them, and a study on one fabric or one filter says little about the piece in your hand.
Other gemstones
Clasp & Lens describes materials from the public record and does not appraise, grade or test pieces; what a listing states is the supplier's statement. If a piece causes a rash, take it off; a reaction that spreads or blisters is a doctor's question, and sunglasses are no substitute for impact-rated eye protection where that is required.